The thermolite knit cap features the many benefits of thermolite polyester combined for lightweight packable warmth. Thermolite polyester is a lightweight fiber providing breathability and warmth while moving moisture from the body by combining a thermally efficient polymer with a micro-tested hollow core fiber that heats up quickly and retains warmth. This is a great basic cap where warmth and dryness in a lightweight design is important. It is also supported by wigwam and its 110+ year history and reputation as a quality family owned business that stands behind their products. This item is made in the USA and carries the wigwam 2-year guarantee. Visit www.wigwa,.com for more details